Touch panels are provided with sensors that detect the position where the touch panel surface is pressed by an object (e.g., a finger). Each of such sensors includes first electrodes and second electrodes, which extend perpendicularly to each other. As is well known in the art, an insulating layer is interposed between the first electrodes and the second electrodes.
The first electrodes and the second electrodes comprise a mesh made up of intersecting fine lines of metal, which are perpendicular to each other (see Japanese Laid-Open Patent Publication No. 2011-517355 (PCT)). Spaces that are surrounded by the intersecting fine lines of metal also are referred to as cells. Since the fine lines of metal intersect perpendicularly with respect to each other, each of the cells is of a square shape. The fine lines of metal mostly comprise fine lines of silver (Ag) in view of electroconductivity, cost, color, etc., which are taken into account.
As disclosed in Japanese Laid-Open Patent Publication No. 2011-074308, a first electrode layer, which includes the first electrodes arranged in the foregoing manner, or a second electrode layer, which includes the second electrodes arranged in the foregoing manner, is applied to a display device, a board, an optical sheet, or the like by an optically clear adhesive (OCA). Since the first electrode layer or the second electrode layer is shaped convexly toward the insulating layer that serves as a base, steps are formed between the insulating layer and the first electrode layer or the second electrode layer. The OCA is required to adequately cover both the insulating layer and the first electrode layer or the second electrode layer, regardless of the steps (improved step conformability).